Submission #651680

#	Time	Username	Problem	Language	Result	Execution time	Memory
651680		rafatoa	Connecting Supertrees (IOI20_supertrees)	C++17	56 / 100	207 ms	22156 KiB

supertrees

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#pragma GCC optimize ("Ofast")

#define double ld
const int inf = 2e9;
const int INF = 4e18;

#define F first
#define S second
#define vi vector<int>
#define vvi vector<vi>
#define pi pair<int, int>
#define vpi vector<pi>
#define vb vector<bool>
#define vvb vector<vb>
#define pb push_back
#define read(a) for(auto &x:a) cin >> x;
#define print(a) for(auto x:a) cout << x << " "; cout << "\n";
#define rs resize
#define as assign
#define vc vector<char>
#define vvc vector<vc>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

#define ppb pop_back
#define MP make_pair

// #define int ll

void build(vvi b);

struct DSU{
    int n;
    vi link, sz;
    void init(int x){
        n = x;
        link.clear(); sz.clear();
        link.resize(n); sz.resize(n);
        for(int i=0; i<n; i++)
            link[i] = i, sz[i] = 1;
    }
    int find(int x){
        if(x == link[x]) return x;
        return link[x] = find(link[x]);
    }
    bool same(int a, int b){
        return find(a) == find(b);
    }
    void unite(int a, int b){
        a = find(a), b = find(b);
        if(a == b) return;
        if(sz[a] < sz[b]) swap(a, b);
        sz[a] += sz[b];
        link[b] = a;
    }
};

int construct(vvi p){
    int n = p.size();
    for(int i=0; i<n; i++)
    for(int j=i+1; j<n; j++)
        if(p[i][j] == 3) return 0;

    vvi b(n, vi(n, 0));
    
    DSU dsu;
    dsu.init(n);
    for(int i=0; i<n; i++)
    for(int j=i+1; j<n; j++)
        if(p[i][j] > 0) dsu.unite(i, j);

    vvi comp(n);
    for(int i=0; i<n; i++)
        comp[dsu.find(i)].pb(i);
    
    for(int i=0; i<n; i++){
        if(comp[i].size() <= 1) continue;
        DSU dsu2;
        dsu2.init(n);
        for(int j=0; j<comp[i].size(); j++)
        for(int k=j+1; k<comp[i].size(); k++)
            if(p[comp[i][j]][comp[i][k]] == 0) return 0;
            else if(p[comp[i][j]][comp[i][k]] == 1) dsu2.unite(comp[i][j], comp[i][k]);
        
        for(int j=0; j<comp[i].size(); j++)
        for(int k=j+1; k<comp[i].size(); k++)
            if((dsu2.same(comp[i][j], comp[i][k]) && p[comp[i][j]][comp[i][k]] == 2) ||
                (!dsu2.same(comp[i][j], comp[i][k]) && p[comp[i][j]][comp[i][k]] == 1)) return 0;
        
        vvi sect(n); vi lims;
        for(int j=0; j<comp[i].size(); j++)
            sect[dsu2.find(comp[i][j])].pb(comp[i][j]);
        
        for(int j=0; j<n; j++){
            if(sect[j].empty()) continue;
            for(int k=0; k<sect[j].size()-1; k++)
                b[sect[j][k]][sect[j][k+1]] = b[sect[j][k+1]][sect[j][k]] = 1;
            lims.pb(sect[j].back());
        }
        
        for(int j=0; j<lims.size()-1; j++)
            b[lims[j]][lims[j+1]] = b[lims[j+1]][lims[j]] = 1;
        if(lims.size() > 1)  b[lims.front()][lims.back()] = b[lims.back()][lims.front()] = 1;
    }

    build(b);
    return 1;
}

Compilation message (stderr)

supertrees.cpp:9:17: warning: overflow in conversion from 'double' to 'int' changes value from '4.0e+18' to '2147483647' [-Woverflow]
    9 | const int INF = 4e18;
      |                 ^~~~
supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:84:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |         for(int j=0; j<comp[i].size(); j++)
      |                      ~^~~~~~~~~~~~~~~
supertrees.cpp:85:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   85 |         for(int k=j+1; k<comp[i].size(); k++)
      |                        ~^~~~~~~~~~~~~~~
supertrees.cpp:89:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |         for(int j=0; j<comp[i].size(); j++)
      |                      ~^~~~~~~~~~~~~~~
supertrees.cpp:90:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   90 |         for(int k=j+1; k<comp[i].size(); k++)
      |                        ~^~~~~~~~~~~~~~~
supertrees.cpp:95:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   95 |         for(int j=0; j<comp[i].size(); j++)
      |                      ~^~~~~~~~~~~~~~~
supertrees.cpp:100:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |             for(int k=0; k<sect[j].size()-1; k++)
      |                          ~^~~~~~~~~~~~~~~~~
supertrees.cpp:105:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  105 |         for(int j=0; j<lims.size()-1; j++)
      |                      ~^~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 0 / 19
• Subtask 4: 35 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4